Apparatus for inspecting a substrate

ABSTRACT

The apparatus for inspecting a substrate of the present invention comprises substrate holding member for holding a substrate to be inspected, a driving mechanism for raising the substrate holding member to a predetermined angle or less, a position coordinate detecting section provided at side edge of the substrate in at least two directions, for detecting coordinates of a defect present in the substrate, an observation system supporting section provided for supporting a micro observation system and moving on the surface of the substrate, and a controlling section for controlling of the movement of the micro observation system of the observation system supporting section to correspond to a defect present in the substrate, on the basis of the position coordinates of the defect detected by the position coordinate detecting section.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation-in-Part application of U.S. patent applicationSer. No. 09/158,362, filed Sep. 22, 1998, now U.S. Pat. No. 6,362,884,the entire contents of which are incorporated herein by reference.

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent applications No. 9-258552, filed Sep. 24,1997; and No. 10-264342, filed Sep. 18, 1998, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus for inspecting defects ina substrate such as a glass substrate for a liquid crystal display(LCD).

Of conventionally-known apparatuses for inspecting defects of LCD glasssubstrates, some apparatuses are known in which defects (e.g., scratch)formed in the surface of the glass substrate can be checked by using amacro observation and a micro observation interchangeably. In the macroobservation, light is applied onto the surface of the glass substrateand then optical change of the reflected light is observed, therebydetecting the defects. In the micro observation, the defects found bythe macro observation are magnified and observed.

For example, Jpn. Pat. Appln. KOKAI No. 5-322783 employs the macroobservation system and the micro observation system which are set so asto correspond to an X-Y stage designed movable horizontally in X and Ydirections. In the apparatus, the macro observation or the microobservation is performed by mounting a substrate on the X-Y stage andbringing a portion of the substrate to be inspected (defect) into anobservation filed of the macro observation system or the microobservation system by moving the X-Y stage two-dimensionally in the Xand Y directions.

Recently, the size of the glass substrate tends to be increased with anenlargement of LCD. In the case where such a large glass substrate isinspected by using the inspecting apparatus having the X-Y stage whichis movable horizontally and two-dimensionally (X, Y directions), fourtimes as large as the area of the glass substrate is required as a spacefor moving the X-Y stage. Therefore, the substrate inspecting apparatusis inevitably large with the increase of the glass substrate.

Furthermore, in the conventional inspection apparatus thus constructed,it is difficult to inspect a small scratch since the surface of thesubstrate is far away from an eye position of the inspector. Moreover,it is difficult to obtain positional data of the defect found in thesurface of the substrate. Accordingly, it has been impossible to inspectthe substrate highly accurately.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide an substrate inspectingapparatus capable of detecting a defect of the substrate efficientlywith high accuracy as well as to provide the apparatus in a reducedsize.

The substrate inspecting apparatus of the present invention comprisessubstrate holding member for holding a substrate to be inspected, adriving mechanism for raising the substrate holding member to apredetermined angle or less, a position coordinate detecting sectionprovided at side edge of the substrate in at least two directions, fordetecting coordinates of a defect present in the substrate, anobservation system supporting section provided for supporting a microobservation system and moving on the surface of the substrate, and acontrolling section for controlling of the movement of the microobservation system of the observation system supporting section tocorrespond to a defect formed present in the substrate, on the basis ofthe position coordinates of the defect detected by the positioncoordinate detecting section.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate presently preferred embodiments ofthe invention, and together with the general description given above andthe detailed description of the preferred embodiments given below, serveto explain the principles of the invention.

FIG. 1 is a perspective view showing a structure of a substrateinspecting apparatus according to an embodiment of the presentinvention;

FIG. 2 is a side view showing a structure of the substrate inspectingapparatus according to the embodiment of the present invention;

FIG. 3 is a top plan view showing a structure of the substrateinspecting apparatus according to the embodiment of the presentinvention;

FIG. 4 is a view showing a structure of a transmission linear lightaccording to an embodiment of the present invention;

FIG. 5 is a view showing a structure of a position detector according toan embodiment of the present invention;

FIG. 6 is a view showing how to inspect a substrate, according to anembodiment of the present invention;

FIG. 7 is a view showing a holder according to an embodiment of thepresent invention;

FIG. 8 is a view showing a structure of the position detector accordingto an embodiment of the present invention;

FIG. 9 is a view showing a structure of the position detector accordingto another embodiment of the present invention;

FIG. 10 is a view showing a structure of the position detector accordingto a further embodiment of the present invention;

FIG. 11 is a perspective view of the substrate inspecting apparatusaccording to an embodiment of the present invention;

FIG. 12 is a side view of the substrate inspecting apparatus accordingto the embodiment of the present invention;

FIG. 13 is a side view of the substrate inspecting apparatus accordingto another embodiment of the present invention;

FIG. 14 is a perspective view showing the position detector employed inthe substrate inspecting apparatus according to the embodiment of thepresent invention;

FIG. 15A is a top view of the guide movement member and showing theretracting mechanism employed in the substrate inspecting apparatus ofthe present invention;

FIG. 15B is a side view of the guide movement member and showing theretracting mechanism employed in the substrate inspecting apparatus ofthe present invention;

FIG. 15C is a top view of the guide movement member and showing theretracting mechanism employed in the substrate inspecting apparatus ofthe present invention; and

FIG. 15D is a side view of the guide movement member and showing theretracting mechanism employed in the substrate inspecting apparatus ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 to 3 are views showing a structure of the substrate inspectingapparatus according to Embodiment 1 of the present invention. FIGS. 1, 2and 3 show its perspective view, side view, and top plan view,respectively. In FIGS. 1 to 3, a holder 2 for holding a substrate 3 isprovided on the main apparatus 1. As shown in FIG. 2, the holder 2 whosebasal portion is supported by a supporting shaft 15 rotatably to themain apparatus 1. A pulley 16 is set in the periphery of the supportingshaft 15. The main apparatus 1 has a motor 18. A ring-form belt 17 isstretched between a rotation shaft 181 of the motor 18 and the pulley16. When rotational driving force generated by the motor is transmittedfrom the rotation shaft 181 to the pulley 16 by way of the belt 17, theholder 2 can be raised from a horizontal posture up to a positionindicated by two-dot and dashed line, in a rotating manner around thesupporting shaft 15. In other words, the holder 2 is raised up to apredetermined angle θ and allowed to stand in an inclined posture.

The holder 2 takes a frame form and mounts the large substrate 3 (e.g.,a glass substrate for an LCD) thereon and holds it by the peripheralportion. The holder 2 has a square-form hollow portion surrounded by theperipheral portion and its area is slightly smaller than the substrate3. The holder 2 has a plurality of substrate urging members 201 (formedof cylindrical pins) along the peripheral portions in the X-axis andY-axis directions. The urging members 201 are arranged so as to protrudeslightly from the surface of the holder 2. The substrate 3 is positionedat a right place on the holder 2 by bringing two sides of the substrate3 into contact with a side portion of each of the substrate urgingmembers 201. The peripheral portion of the substrate 3 is adsorbed ontothe surface of the holder 2 by use of an aspirator (not shown) through aplurality of holes (adsorptive pads) (not shown), which are formed alongthe entire peripheral portion of the holder 2. By virtue of thismechanism, the substrate 3 is held on the holder 2 without falling out.

Furthermore, guide scales 19, 20 are arranged on the holder 2 alongsides of the substrate 3 in the X-axis and Y-axis directions. The guidescales 19, 20 are responsible for detecting coordinates of the defectpresent in the substrate 3. The guide scale 19 has a reflector (mirror)215 of the Y-axis direction. The guide scale 20 has a reflector (mirror)216 of the X-axis direction. The reflectors 215, 216 are providedmovably along the guide scales 19, 20, respectively. A beam splitter 214is fixed on the holder 2 at a point of intersection of extension linesof the guide scales 19, 20. A light source section 21 (described later)is disposed on a position slightly separate from the guide scale 20(extension line of the guide scale 20) with respect to the beam splitter214.

As shown in FIGS. 1 to 3, a pair of guide rails 4, 4 are arranged inparallel to the Y-axis direction along both sides of the holder 2 on themain apparatus 1. An observation unit supporting section 5 is arrangedabove the holder 2 so as to cross over the holder 2. The observationunit supporting section 5 is formed movably along the guide rails 4, 4in the Y-axis direction above the substrate 3, or above the holder 2.

The observation unit supporting section 5 has an observation unit 6which is supported movably along a guide rail (not shown) in the X-axisdirection perpendicular to the moving direction (Y-axis) of theobservation unit supporting section 5. Furthermore, the observation unitsupporting section 5 is equipped with a linear transmission light source7 so as to face a moving line of the observation unit 6. The lineartransmission light source 7 is arranged along the X-axis direction on arear board 51 of the supporting section 5, which moves under the holder2. Accordingly, the substrate 3 is illuminated by transmission lightlinearly from the bottom. The linear transmission light source 7 isdesigned movable in the Y axis direction together with the observationunit supporting section 5.

The observation unit 6 has a micro observation unit 9 equipped with areference light 8 for use in the micro observation and a partialillumination macro light 10 for use in macro observation. The referencelight source 8, which plays a role in identifying defect positions onthe substrate 3, projects an optically-converged spot-light upon thesurface of the substrate 3. The reflected spot light from the surface ofthe substrate 3 is brighter than the light emitted from the partialillumination macro light 10 and reflected at the surface of thesubstrate 3. It is therefore possible to visually perform an observationeven if the macro observation process is performed using the partialillumination macro light 10.

The micro observation unit 9 has a microscopic function including anobjective lens 91, an ocular lens 92 and an incident light source (notshown). Therefore, an image of the surface of the substrate 3 can beobserved through the ocular lens 92 via the objective lens. The microobservation unit 9 is equipped with a TV camera 93 through a tri-lensbarrel. When the visual micro observation is not required, a TV camera93 alone may be set on a liner cylinder. The image of the substratesurface obtained through the objective lens 91 is photographed by the TVcamera 93 and sent to a controller 11. The controller 11 instructed todisplay the photographed image on the TV monitor 12. To the controller11, an input section 111 is connected so as to enable an inspector toinput data and to instruct operations.

The partial illumination macro light 10 is used for the macroobservation. The surface of the substrate 3 on the holder 2 is partiallyilluminated with the macro light 101. The incident angle of the partialillumination macro light source 10 with the substrate surface can becontrolled at the most suitable angle for the macro observation.

FIG. 4 is a view showing a structure of the linear transmission light 7.As shown in FIG. 4, the linear transmission light 7 has a light sourcesection 71 and a solid glass rod 72. The light emitted from the lightsource section 71 is diffusely reflected by the reflecting board 712 andinjected into an end of the glass rod 72. The incident light istransmitted through the glass rod 72 while totally reflected andsimultaneously dispersed by white stripes 73 (which have been coated andprocessed into stripes) on a rear portion (lower portion) of the glassrod 72. As a result, linear light is emitted upwardly by virtue of alens-like function of the glass rod 72. The structure of the lineartransmission light is not limited to the aforementioned one. Forexample, a fluorescent lamp may be employed as the linear illumination.

FIG. 5 is a view showing a structure of a position detector of thesubstrate inspecting apparatus of the present invention. In FIG. 5, likereference numerals are used to designate like structural elementscorresponding to those in FIG. 3. The position detector has a lightsource section 21, a beam splitter 214 and reflectors (mirrors) 215,216. The light source section 21 is formed of a laser light source 211and cylindrical lenses 212, 213. The beams splitter 214 splits the laserlight emitted from the laser light source 211 into light beams in theX-axis and Y-axis directions. The reflectors 215, 216 are respectivelyformed on the guide scales 19, 20. The beam splitter 214 and thereflectors 215, 216 are vertically set at a right angle or an acuteangle with the substrate surface 3.

The laser light emitted from the laser light source 211 is transmittedthrough the cylindrical lenses 212, 213 and finally emitted in theX-axis direction in the form of a planar light virtually perpendicularto the surface of the substrate 3. The planar laser light is split intotwo beams in the X-axis and Y-axis directions. The laser light beam inthe X-axis direction is reflected by the reflector 216 and proceeds inthe perpendicular direction, namely, the Y-axis direction, in the formof a planar laser light 217 virtually perpendicular to the surface ofthe substrate 3. On the other hand, the laser light beam in the Y-axisdirection is reflected by the reflector 215 and proceeds in theperpendicular direction, namely, the X-axis direction, in the form of aplaner laser light 218 virtually perpendicular to the surface of thesubstrate 3.

The inspector moves the reflector 215 along the guide scale 19 to permitthe laser light 218 to correspond with the defect present in thesubstrate surface. In the same manner, the inspector moves the reflector216 along the guide scale 20, thereby permitting the laser light 217 tocorrespond with the defect. Thereafter, when the inspector turns on aswitch (not shown), values of the guide scales 19, 20, that is, movingamounts of the reflectors 215, 216 in the X-axis direction and Y-axisdirection from their origins can be detected by respective detectors(not shown) of the guide scales 19, 20, as coordinates (X, Y) of thedefect. The detected results are output from the detector to thecontroller 11. Note that the origin of the coordinate of the reflector215 is present at the forefront side of the guide scale 19. The originof the coordinate of the reflector 216 is present at the rightmost endof the guide scale 20 (see FIG. 3).

FIG. 6 shows how to inspect a substrate by use of the inspectingapparatus of the present invention. As shown in FIG. 6, an entire-areailluminating macro light source 30 is set above the main apparatus 1.The macro light source 30 irradiates the entire area of the surface ofthe substrate 3 on the holder 2. The macro light source 30 isconstituted of a metal halide lamp 31 serving as a point light source, areflecting mirror 32 arranged so as to face the metal halide lamp 31,and a fresnel lens 33 arranged below the reflecting mirror 32. Thereflecting mirror 32 is tilted at an angle of 45° with the mainapparatus 1 and plays a role in reflecting light incident from the metalhalide lamp 31 and injected into the fresnel lens 33. The fresnel lens33 converges the light reflected by the reflecting mirror 32, as shownin the figure, and injects the converged light over the entire surfaceof the substrate 3 on the holder 2. Note that, as shown in FIG. 1, themain apparatus 1 has a Y-scale 13 for detecting the position coordinateof the observation unit supporting section 5 in the Y-axis direction. AnX-scale 14 is provided on the observation unit supporting section 5 fordetecting the position coordinate of the observation unit 6 in theX-axis direction.

The controller 11 shown in FIG. 1 is responsible for not only positioncoordinates (X, Y) of the defect detected by the guide scales 19, 20 andposition coordinates of the observation unit supporting section 5 andthe observation unit 6 detected by the Y-scale 13 and the X-scale 14,but also movement control of the observation unit supporting section 5and the observation unit 6 by a driving mechanism (not shown).Furthermore, the controller 11 has a memory (not shown) for storing dataof the interval X0 between an optical axis of the reference light source8 and an optical axis of the objective lens 91. The control 11 controlsmovements of the observation unit supporting section 5 and theobservation unit 6 so as to permit the optical observation axis of theobjective lens 91 of the micro observation unit 9 to correspond with theposition coordinates (X, Y) of the defect in the substrate 3 given bythe guide scales 19, 20.

While a spot of the reference light 8 is being focused on the defectpresent in the substrate 3, the controller 11 controls the movements ofthe observation unit supporting section 5 and the observation unit 6upon receiving a predetermined instruction given by the inspector fromthe input section 111. To explain more specifically, first, the positioncoordinates of the defect are obtained from the position coordinate dataof the X-scale 13 and Y-scale 13, detected by detectors (not shown) ofthe Y scale 13 and the X-scale 14. Then, on the basis of the coordinatedata thus obtained and the data of the interval X0 between the opticalaxis of the reference light 8 and the optical axis of the objective lens91, the observation unit supporting section 5 and the observation unit 6are moved in such a way that the observation axis of the objective lens91 corresponds to the defect present in the substrate 3.

Now, how to operate the substrate inspecting apparatus thus constructedwill be explained. In the case of the macro observation of the surfaceof the substrate 3, the operation is performed as follows. First, theinspector gives a predetermined instruction from the input section 111to the controller 11. Then, the controller 11 instructs the observationunit supporting section 5 to move backward to the initial position shownin FIG. 1. Thereafter, the inspector places the substrate 3 onto theholder 2 placed horizontally. Upon setting of the substrate 3 at a rightposition on the holder 2 by a plurality of substrate urging members 201,the substrate 3 is adsorbed onto the holder 2 by the aspirator so as notto drop from the holder 2. In this way, the macro inspecting observationof the defect is initiated.

Next, we will explain how to perform the macro observation of the entiresurface of the substrate 3 using the macro light, at one time. First,the motor 18 shown in FIG. 2 is driven by the inspector, therebyrotating the supporting shaft 15 through the pulley 16 via the rotationshaft 181 and the belt 17. The holder 2 is then tilted at apredetermined angle θ, preferably 30-45° around the supporting shaft 15.Thereafter, the motor is stopped to terminate the movement of the holder2. Subsequently, a metal halide lamp 31 shown in FIG. 6 is lighted on bythe inspector. The light from the metal halide lamp 31 is converged bythe reflection mirror 32 and the fresnel lens 33, and then applied ontothe entire surface of the substrate 3 on the holder 2. While maintainingthis state, the substrate 3 on the holder 2 is visually inspected by thenaked eye of the inspector for scratches. Note that the defect isinspected while not only staying the holder 2 at a predetermined anglebut also swinging the holder 2 at a predetermined angular range aroundthe supporting shaft 15 by changing a rotation direction of the motor 18periodically under control of the controller 11. In the later case, itis possible to change the angle of the light supplied from the metalhalide lamp 31 incident onto the substrate 3, so that the substrate 3can be inspected under the illumination light incident from variousangles.

FIG. 7 is a view showing the holder 2 having the substrate 3 with adefect. When the inspector recognizes a defect a in the substrate 3during the macro observation, as shown in FIG. 7, the inspector movesthe reflector 215 along the guide scale 19 so as to permit the laserlight 218 to correspond with the defect a. Subsequently, the inspectormoves the position reflector 216 along the guide scale 20 to permit thelaser light 217 to correspond with the defect a. At this point, theposition coordinates (X, Y) of the defect a are determined by readingthe scale values of the guide scales 19, 20 at which the reflectors 215,216 are located by the detectors of the guide scales 19, 20. Thedetected results are output from the detector into the controller 11. Inthis way, the data showing the position coordinates (X, Y) of the defecta is stored in the memory of the controller 11. Thereafter, the sameoperation is repeated whenever the inspector recognizes a defect in thesubstrate 3 and the data indicating the position coordinates (X, Y) ofeach defect is stored in the controller 11. After the macro observationover the entire surface of the substrate 3 is completed, the motor 18 isdriven again by the inspector to rotate the supporting shaft 15 in theopposite direction as mentioned above, through the pulley 16 via therotation shaft 181 and the belt 17. In this way, the holder 2 isreturned to a horizontal posture initially taken.

Next, we will explain how to perform the micro observation of eachdefect which has been found by the macro observation by use of the microobservation unit 9. First, the position coordinates (X, Y) of the defectstored in the memory are read out by the controller 11. Then, theobservation unit supporting section 5 and the observation unit 6 aremoved along the guide rails 4, 4, and a guide rail (not shown) in such amanner that the observation axis of the objective lens 91 in the microobservation unit 9 corresponds to the coordinates under the control ofthe controller 11.

With this operation, the defect present in the substrate 3, i.e., animage of the defect obtained through the objective lens 91 can bemicroscopically observed by looking into the ocular lens 92 of the microobservation unit 9. In the case where the image of the defect found inthe surface of the substrate 3 is photographed by the TV camera 93 anddisplayed on the TV monitor 12, the micro observation of the defect isperformed by watching the image on the TV display.

Next, we will explain the case in which a defect is inspected by themacro observation using a partial illumination macro light source 10 andthen subjected to the micro observation performed by the microobservation unit 9. In this case, the inspector places the substrate 3at the right position on the holder 2 and adsorbed in the same manner asabove. Then, the partial illumination macro light source 10 of theobservation unit 6 is lighted on by the inspector to partially irradiatethe surface of the substrate 3 mounted on the holder 2.

Subsequently, as shown in FIG. 3, the inspector operates an operationsection (joystick, not shown) to move the observation unit 6 linearlyalong the guide rail of the observation unit supporting section 5 in theX-axis direction, and to move the observation unit supporting section 5linearly along the guide rails 4, 4 in the Y-axis direction. Whileraster-scanning over the substrate 3 by the macro light 101, theinspector visually inspects scratches and spots over the entire surfaceof the substrate 3. In this case, the irradiation angle of the macrolight 101 with the substrate 3 is adjusted so as to perform partialmacro observation suitably.

In the partial macro observation using the partial illumination macrolight source 10, when the inspector recognizes the defect in thesubstrate 3 under the illumination of the macro light 101, theobservation unit 6 is moved along the X-axis and Y-axis by operating theoperation section by the inspector so as to focus the spotlight of thereference light source 8 on the defect present in the substrate 3.

The position coordinates of the defect on the surface of the substrate 3are determined by the controller 11 on the basis of the positioncoordinate data detected by the Y-scale 13 and X-scale 14. Subsequently,using the position coordination data and the previously stored dataindicating the interval X0 between the optical axis of the referencelight source 8 and the optical axis of the objective lens 91, themovements of the observation unit supporting section 5 and theobservation unit 6 are controlled so as to permit the optical axis ofthe objective lens 91 to correspond with a specified defect present inthe substrate 3.

Since the specified defect is brought into the center of the visualfield of the objective lens 91 by the aforementioned operation, themicro observation of the defect can be made through the objective lens91. At the same time, the defect obtained by the objective lens 91 isphotographed by the TV camera 93. Therefore, the micro observation maybe made on the TV monitor 12 by the inspector. In this case, theincident light can be used interchangeably with the transmission lightdepending upon types of the defects and substrates.

When the inspector instructs the macro observation again to thecontroller 11 through the input section 111, the defect is brought backwithin the illumination range of the macro light 101, so that aninspector can check the defect under the macro observation. If anotherdefect is continuously observed, the same operation as mentioned abovemay be repeated. After the defect inspection is completed, the inspectorgives a predetermined instruction to the controller 11 through the inputsection 111 to return the observation unit supporting section 5 to theinitial position. The inspector removes the inspected substrate 3 fromthe holder 2, a new substrate 3 is mounted on and held by the holder 2.

In the case explained above, the macro observation is performed whilethe surface of the substrate 3 mounted on the holder 2 is partiallyilluminated with the partial illumination macro light source 10 and thenthe micro observation is performed when the defect is recognized in thesubstrate 3. In the case where only the macro observation is performedunder illumination of the partial illumination macro light source 10,the operation is performed as follows. First, the inspector moves backthe observation unit supporting section 5 to the initial position andmounts the substrate 3 on the holder 2. Then, the partial illuminationmacro light source 10 is lighted on to partially irradiating the surfaceof the substrate 3 on the holder 2 with the macro light 101 by theinspector. While the observation unit 6 is moved linearly in the X-axisdirection along the guide rail of the observation unit supportingsection 5 by operating the operation section and the observation unitsupporting section 5 is further linearly moved in the Y-axis directionalong the guide rails 4, 4, the substrate 3 is raster-scanned by use ofthe macro light 101. In this manner, the defect can be visuallyinspected over the entire surface of the substrate 3 by the inspector.

In this case, if the spotlight of the reference light source 8 isfocused on each defect under the illumination of the macro light 101,the position coordinates of the defect are detected by detectors (notshown) respectively set at the X-scale and Y-scale. The detectedposition coordinates can be stored in the memory of the controller 11.

When the defect whose coordinate data is stored in the memory of thecontroller 11 is subjected to the micro observation by the microobservation unit 9, the operation is as follows. First, the inspectormoves back the observation unit supporting section 5 to the initialposition. Then, the inspector mounts the substrate 3 on the holder 2.The transmission linear light source 7 is lighted on, therebyirradiating the substrate linearly from the bottom of the holder 2 inthe X-axis direction. Subsequently, the micro observation unit 9 ismoved linearly under control of the controller 11 along the guide railof the observation unit supporting section 5 in the X-axis direction.Consequently, the objective lens 91 is moved linearly in the X-directionalong the transmission linear light source 7. Furthermore, theobservation unit supporting section 5 is moved linearly in the Y-axisdirection along the guide rails 4, 4. In this manner, a predeterminedrange of the substrate 3 can be observed microscopically via theobjective lens 91. At the same time, the surface of the substrate 3 isphotographed by the TV camera 93 and the image thereof is displayed onthe TV monitor 12. Also in this case, the transmission light can beinterchangeably used with the incident light depending upon the type ofthe substrate 3 and the defect.

According to the substrate inspecting apparatus of the presentinvention, the substrate 3 is raised at a predetermined angle byrotating the holder 2 having the substrate 3 held thereon, about thesupporting shaft 15. By virtue of the operation, the substrate 3 isplaced at a position close to an inspector's eye, so that the inspectorcan perform the macro inspection of the substrate 3 in an easy posture.In addition, the laser light source section 21, the beam splitter 214,the reflectors 215, 216, and the guide scales 19, 20 for use indetecting the position of the defect present in the substrate 3, areintegrally provided on the rotatable (up and down) holder 2. It istherefore possible to detect the coordinates of the defect on thesubstrate 3 always in the same plane whenever the holder 2 is tilted atany angle. As a result, the coordinates of the defect can be detectedhighly accurately, and therefore a complicated process for amending thecoordinate data depending upon the tilt angle is no longer required. Theposition coordinates (X, Y) of the defect can be determined only bydetecting the positions of the reflectors 215 and 216 corresponding tothe detect while manually moving them along the guide scales 19, 20(which are provided along the side edges of the substrate 3). Therefore,the positional data of the defect can be easily obtained.

The observation unit 6 can be moved to any position on the substrate 3by moving the observation unit supporting section 5 along one directionon the substrate 3 and moving the observation unit 6 in the directionperpendicular to the moving direction of the observation unit supportingsection 5. As a result, the area of the holder 2 can be set at almostthe same value as the substrate 3. As a result, miniaturization of thesubstrate inspecting apparatus can be realized. In addition, the area inwhich the substrate detection apparatus is placed, can be drasticallyreduced.

FIG. 8 is a view showing the structure of the position detector of thesubstrate inspecting apparatus according to Embodiment 2 of the presentinvention. In FIG. 8, like reference numerals are used to designate likestructural elements corresponding to those in FIG. 7. The positiondetector is applied to the substrate inspecting apparatus shown inEmbodiment 1. The position detector is constituted of two light sourcesections 21, 22 and reflectors (mirrors) 215, 216. Each of the lightsource sections 21, 22 has the laser light source 211 and thecylindrical lenses 212, 213 shown in FIG. 5.

The holder 2 has the guide scales 19, 20 formed in the Y-axis directionand the X-axis direction along a side of the substrate 3, as shown inFIG. 8. The guide scales 19, 20 play a role in detecting positioncoordinates of a defect present in the substrate 3. The guide scale 19is equipped with the reflector (mirror) 215 in the Y-axis direction. Theguide scale 20 is equipped with the reflector (mirror) 216 in the X-axisdirection. The reflectors 215, 216 are movably provided along the guidescales 19, 20, respectively. The reflectors 215, 216 are set verticallyat a right angle or an acute angle with the surface of the substrate 3.The holder 2 has the light source 21 at a position slightly apart fromthe right side of the guide scale 20 (the extension line of the guidescale 20). The light source section 22 is set at a position slightlyahead the guide scale 19 (the extension line of the guide scale 19).

The laser light emitted from the laser light source 211 of the lightsource section 21 transmits through the cylindrical lenses 212, 213 andfinally emitted in the X-axis direction in the form of a planar laservirtually perpendicular to the surface of the substrate 3. The laserlight is reflected by the reflector 216 in the perpendicular direction,namely, in the Y-axis direction, to become planar-form laser light 217virtually perpendicular to the surface of the substrate 3. The laserlight emitted from the laser light source 211 of the light sourcesection 22 transmits through the cylindrical lenses 212, 213, andfinally emitted in the Y-axis direction in the form of a planar laserlight virtually perpendicular to the surface of the substrate 3. Thelaser light is reflected by the reflector 215 in the perpendiculardirection, namely, in the X-axis direction, to become planer-form laserlight 218 virtually perpendicular to the surface of the substrate 3.

In the same manner as in Embodiment 1, the inspector moves the reflector215 along the guide scale 19 to permit the laser light 218 to correspondwith the defect a formed in the surface of the substrate 3. Similarly,the inspector moves the reflector 216 along the guide scale 20 to permitthe laser light 217 to correspond with the defect a. Thereafter, theinspector turns on the foot switch. The values of the guide scales 19,20, that is, the moving amounts of the reflectors 215, 216 from theorigins (the foremost position of the guide scale 19, the rightmostposition of the guide scale 20 in FIG. 3) in the Y-axis and X-axisdirections are determined by the detectors (not shown) of the guidescales 19, 20, as coordinates (X, Y) of the defect a. The detectionresults are output from the detectors to the controller 11.

According to the substrate inspecting apparatus according to Embodiment2, the positional data of the defect can be easily obtained by movingthe reflectors 215, 216 manually by the inspector.

FIG. 9 is a view showing the structure of the position detector of thesubstrate inspecting apparatus according to Embodiment 3 of the presentinvention. In FIG. 9, like reference numerals are used to designate likestructural elements corresponding to those in FIG. 7. The positiondetector can be applied to the substrate inspecting apparatus shown inEmbodiment 1.

In FIG. 9, holding members 301, 302 are respectively provided on one ofside surfaces of the holder 2 in the Y-axis direction and on one of sidesurfaces of the holder 2 in the X-axis direction, respectively. Thesurfaces of the holding members 301, 302 are lower than the surface ofthe holder 2, so that a step is formed between them. The holding members301 and 302 are respectively equipped with guide rails 303, 304 alongthe Y-axis direction and the X-axis direction of the side edge of theholder 2. Furthermore, guide moving sections 305 and 306 are movablyprovided along the guide rails 303, 304 so as to cross over the guiderails 303, 304.

The holding members 301 and 302 have a pair of pulleys 307, 308, and apair of pulleys 309, 310 supported by shafts and positioned respectivelyat both ends. A belt 311 and a belt 312 are respectively stretchedbetween the pulley 307 and the pulley 308, and between the pulley 309and pulley 310, in the form of a ring. The guide moving section 305 isfixed at a part of the belt 311. The guide moving section 306 is fixedat a part of the belt 312. To the pulleys 307, 310, respective rotationaxis 315, 316 of the motors 313, 314 are inserted, respectively. A pairof optical sensors 317, 318 and a pair of optical sensors 319, 320 arerespectively provided at one of side surfaces in the Y-axis directionand one of side surfaces in the X-axis direction of the holder 2, fordetecting the presence of the guide moving sections 305, 306.

The guide moving section 305 is equipped with the reflector (mirror) 215in the Y-axis direction. The guide moving section 306 is equipped withthe reflector (mirror) 216 in the X-axis direction. These reflectors arevertically provided at a right angle or an acute angle with the surfaceof the substrate 3. A holding member 321 is provided at a point ofintersection between the holding members 301 and 302. The holding member321 is virtually as high as the holder 2. The beam splitter 214 isvertically provided on the holding member 321 at a point of intersectionof the extension lines of the guide rails 303, 304, at a right angle oran acute angle with the surface of the substrate 3. The light sourcesection 21 is set on the extension line of the guide rail 304 at aposition slightly apart from the right side of the beam splitter 214.The light source section 21 is formed of the laser light source 211 andthe cylindrical lenses 212, 213 as shown in FIG. 5.

The laser light emitted from the laser light source 211 of the lightsource section 21 transmits through the cylindrical lenses 212, 213, andfinally emitted in the X-direction in the form of a planar laser lightvirtually perpendicular to the surface of the substrate 3. The laserlight is split by the beam splitter 214 into two light beams in theX-direction and Y-direction. The laser light split in the X-axisdirection is reflected by the reflector 216 and proceeds in theperpendicular direction, namely the Y-axis direction, in the form of aplanar laser light 217 virtually perpendicular to the surface of thesubstrate 3. On the other hand, the laser light split in the Y-axisdirection is reflected by the reflector 215 and proceeds in theperpendicular direction, namely, the X-axis, in the form of a planerlaser light 218 virtually perpendicular to the surface of the substrate3.

When the inspector operates the operation section (joystick) to drivethe motor 313, the rotation shaft 315 moves in one direction, with theresult that the belt 311 moves in said one direction along the Y-axisvia the pulleys 307, 308. Alternatively, when the rotation shaft 315 ismoved in the other (opposite) direction by moving the motor 313 byoperating the operation section, the belt 311 moves in the otherdirection along the Y-axis via the pulleys 307, 308. Consequently, thereflector 215 on the guide moving section 305 is moved along the guiderail 303 to permit the laser light 218 to correspond with the defect apresent in the substrate 3.

Furthermore, when the motor 314 is driven by operating the operationsection by the inspector, the rotation shaft 316 is moved in onedirection, with the result that the belt 312 moves in said one directionalong the X-axis via the pulleys 310, 309. Alternatively, when therotation shaft 316 is moved in the other direction (opposite direction)by driving the motor 314 under the control of the operation section, thebelt 312 is moved in the other direction along the X-axis via thepulleys 310, 309. With this operation, the reflector 216 on the guidemoving section 306 is moved along the guide rail 304 to permit the laserlight 217 to correspond with the defect a present in the substrate 3.

Thereafter, the inspector turns on the foot switch. At this time, thevalues of guide scales (not shown) provided on the guide rails 303, 304,that is, moving amounts of the reflectors 215, 216 from the origins(positions of the sensors 318, 319) in the Y-axis direction and theX-axis direction, are detected by the detectors (not shown) of the guidescales as the coordinates (X, Y) of the defect a. The detection resultsare output from the detector to the controller 11.

Note that when the presence of the guide moving section 305 is detectedby the sensor 317 or 318, the driving of the motor 313 is automaticallystopped by the controller 11. This means that the guide moving section305 can be moved back and forth on the guide rail 303 only between theposition corresponding to the sensor 317 and the position correspondingto the sensor 318. Similarly, when the presence of the guide movingsection 306 is detected by the sensor 319 or 320, the driving of themotor 314 is automatically stopped by the controller 11. This means thatthe guide moving section 306 is moved back and forth on the guide rail304 only between the position corresponding to the sensor 319 and theposition corresponding to the sensor 320.

According to the substrate inspecting apparatus of Embodiment 3 of thepresent invention, a single laser light source 21 is used and the guidemoving sections 305, 306 equipped with the reflectors 215, 216 areelectrically driven. It is therefore possible for an inspector tocontrol the movements of the reflectors 215, 216 by operating theoperation section manually. By virtue of this, in a specific case wherea large substrate is inspected, the positional data of the defectpresent far away from the inspector can be readily determined. To movethe guide moving sections 305, 306, a ball screw with a guide and alinear motor may be used.

The substrate inspecting apparatus of Embodiment 3 may be formed bysetting two light source sections on the holder 2 instead of the beamsplitter in the same manner as in Embodiment 2. The light from the lightsources irradiates the reflectors 215, 216, respectively.

FIG. 10 is a view showing a structure of the position detector of thesubstrate inspecting apparatus according to Embodiment 4 of the presentinvention. In FIG. 10, like reference numerals are used to designatelike structural elements corresponding to those in FIG. 7. The positiondetector can be applied to the substrate inspecting apparatus shown inEmbodiment 1. The position detector is constituted of two light sourcesections 401, 402. Each of the light source sections 401, 402 isconstituted of the laser light source 211 and cylindrical lenses 212,213 shown in FIG. 5.

As shown in FIG. 10, the holder 2 has the guide scales 19, 20 along theside edges of the substrate 3 in the Y-axis direction and X-axisdirection, for detecting the position coordinates of the defect presentin the substrate 3. The light source sections 401, 402 are movablyprovided on the guide scales 19, 20, respectively.

The laser light emitted from the laser light source 211 of the lightsource section 401 transmits through the cylindrical lenses 212, 213 andfinally emitted in the X-axis direction in the form of a planar laserlight 403 virtually perpendicular to the surface of the substrate 3.Similarly, the laser light emitted from the laser light source 211 ofthe light source section 402 transmits through the cylindrical lenses212, 213 and finally emitted in the Y-axis direction in the form of aplanar laser light 404 virtually perpendicular to the surface of thesubstrate 3.

In the same manner as in Embodiment 1, the inspector moves the lightsource section 401 along the guide scale 19 to permit the laser light403 to correspond to the defect a in the surface of the substrate 3.Similarly the inspector moves the light source section 402 along theguide scale 20 to permit the laser light 404 to correspond with thedefect a. Thereafter, the inspector turns on the foot switch. The valuesof the guide scales 19, 20, that is, moving amounts of the light sourcesections 401, 402 from the origins (the foremost position of the guidescale 19, the rightmost position of the guide scale 20 in FIG. 10) inthe Y-axis and X-axis directions are determined by the detectors (notshown) of the guide scales 19, 20, as coordinates (X, Y) of the defecta. The detection results are output from the detector to the controller11.

According to the substrate inspecting apparatus of Embodiment 4 of thepresent invention, two laser light source sections 401, 402 are providedon the guide scales 19, 20. Different from the constitutions ofEmbodiments 1 and 2, the beam splitter and reflectors are not used. Theinspector can easily determine the positional data of the defect only bymoving the light sources 401, 402, manually. Note that the substrateinspecting apparatus of Embodiment 4 may be formed in the same manner asin Embodiment 3. That is, the laser light sources 401, 402 are providedon the guide moving sections 305, 306 and the laser light sources 401,402 may be electrically moved along the guide scales 19, 20.

FIGS. 11 and 12 show the structure of a substrate inspecting apparatusaccording to Embodiment 5 of the present invention. FIG. 11 is aperspective view thereof and FIG. 12 is a side view thereof. In FIGS. 11and 12, like reference numerals are used to designate like structuralelements corresponding to those in FIGS. 1 and 2, and any furtherexplanation is omitted for brevity's sake. In the substrate inspectingapparatus shown in FIGS. 1 and 2, the rotation driving force of themotor 18 is transmitted from the rotation shaft 181 to the pulley 16 byway of the belt 17, whereby the holder 2 is lifted from the horizontalposture up to a predetermined angle around the supporting axis. In thesubstrate inspecting apparatus according to Embodiment 5, the holder 2is lifted up in a swinging manner by a link mechanism to a predeterminedangle and allow to stand in an inclined posture.

As shown in FIG. 11, on the main apparatus body 1, a long and narrowhole 501 is formed along the side of the holder 2 arranged horizontally.Through the hole 501, a connecting member 502 is inserted. On the sidesurface of the holder 2, a hook 503 is formed so as to cross at a rightangle with the surface of the holder 2 on which the substrate 3 ismounted. An end of the connecting member 502 is rotatably connected tothe hook 503 via a rotation shaft 504. The other end of the connectingmember 502 is rotatably connected to a moving piece 506 via the rotationshaft 505 below the main apparatus body 1, as shown in FIG. 12.

Furthermore, as shown in FIG. 12, pulleys 509, 510 are providedrespectively at ends of holding members 507, 508 while being supportedby a shaft. The belt 511 is stretched between the pulleys 509 and 510 ina ring form. The moving piece 506 is fixed onto a part of the belt 511.The rotation shaft 512 of a motor (not shown) is inserted in the pulley509.

The inspector operates a holder operation section (not shown) to drivethe motor. At this point, when the rotation shaft 512 is rotatedcounterclockwise, the belt 511 is moved in the “−Y” direction via thepulleys 509, 510. Alternatively, when the rotation shaft 512 is rotatedclockwise by driving the motor, the belt 511 is moved in the “+Y”direction via the pulleys 509, 510. With this movement, the moving piece506 fixed on the belt 511 is moved in the −Y direction and +Y direction(forward and backward to the holder 2).

As shown in FIG. 12, when the moving piece 506 moves in the −Y directionwhile maintaining the holder 2 horizontally, the end of the connectingmember 502 connected to the moving piece 506 rotates clockwise by therotation shaft 505. As a result, the connecting member 502 is graduallylifted up from the inclined posture. In accordance with this movement,the end of the connecting member 502 pushes up the holder 2 via the hook503 while rotating around the rotation shaft 504, with the result thatthe holder 2 is rotated at an angle of about 30° around the supportingshaft 15 and lifted up to a position indicated by a two dot-and-dashline from the horizontal posture, allowing the holder 2 to stand up inan inclined posture. Thereafter, the inspector terminates the movementof the motor to stop the holder 2. Subsequently, the macro observationis performed.

After completion of the macro observation of the entire substrate 3, theinspector operates the holder operation section again to drive themotor. When the rotation axis 512 is rotated clockwise, the moving piece506 is moved in the +Y direction via the pulleys 509, 510 and the belt511. Upon the movement of the moving piece 506 in the +Y direction, theend of the connection member 502 connected to the moving piece 506 isrotated counterclockwise by the rotation axis 505. As a result, theconnecting member 502 is gradually inclined from the stand-up posture.With this movement, the end of the connecting member 502 brings down theholder 2 via the hook 503 while rotating the end of the connectingmember 502 around the rotation shaft 504. Consequently, the holder 2returns in a horizontal posture initially taken. In this state, themicro observation is performed by the inspector. The moving piece 506may be moved back and forth by a well known ball-screw or a linear motorin place of the belt.

As described in the above, it is possible to lift up the holder 2 up toan angle of about 30° by using the link mechanism because of the swingmovement of the holder 2. In addition, since the holder 2 is supportedby the connecting member 502 when lifted up, the macro observation canbe performed while setting the holder 2 in a more stable posture.

FIG. 13 is a side view of the structure of a substrate inspectingapparatus according to Embodiment 6 of the present invention. In FIG.13, like reference numerals are used to designate like structuralelements corresponding to those in FIG. 12, and any further explanationis omitted for brevity's sake. In Embodiment 5, the link mechanism isconstituted by using a single connecting member, whereas the linkmechanism is constituted by using two connecting members in Embodiment6.

As shown in FIG. 13, the proximal end of a first connecting member 601is rotatably connected by a rotation shaft 602 to the main apparatusbody 1 while being supported by the shaft. To the free end of the firstconnecting member 601, a roller 600 moving on the rear surface of theholder 2 is rotatably connected while being supported by the shaft. Tothe position near the free end of the first connecting member 601, anend of a second connecting member 604 is rotatably connected via arotation axis 603. The other end of the second connecting member 604 isrotatably connected to the moving piece 506 via a rotation axis 605below the main apparatus body 1.

As shown in FIG. 13, when the moving piece 506 moves in the −Y directionwhile maintaining the holder 2 in the horizontal posture, the other endof the second connecting member 604 connected to the moving piece 506rotates clockwise by the rotation axis 605. As a result, the secondconnecting member 604 is gradually lifted up from the inclined posture.With this movement, the end of the second connecting member 604 lifts upthe first connecting member 601 while rotating around the rotation axis603. Further, with this movement, the roller 600 of the first connectingmember 601 rotatably moves on the rear surface of the holder 2 andpushes up the holder 2. As a result, the holder 2 is lifted up at anangle of about 60° around the supporting shaft 15 to a positionindicated by a two dot-and-dash line from the horizontal posture,allowing the holder 2 to stand in an inclined posture. After the holder2 is allowed to stand in the inclined posture, the inspector terminatesthe movement of the motor to stop the holder 2. Thereafter, the macroobservation is performed.

When the moving piece 506 moves in the +Y direction, from this state,the other end of the second connection member 604 connected to themoving piece 506 is rotated counterclockwise by the rotation axis 605.As a result, the second connecting member 604 is gradually inclined fromthe stand-up posture. Accordingly, the end of the second connectingmember 604 brings down the first connecting member 601 while rotatingaround the rotation shaft 603. With this movement, the holder 2 isbrought down following the movement of the roller 600 of the firstconnecting member 601. Consequently, the holder 2 returns in ahorizontal posture initially taken. In this state, the micro observationis performed by the inspector.

As described above, the link mechanism is constituted by using twoconnecting members in order to swing the holder 2. With the structure,the holder 2 can be lift up to about an angle of 60° and allowed tostand in an inclined posture. If the holder 2 is lifted up to about 60°by means of one connecting member in Embodiment 5, very long connectingmember is required. As a result, a broad space is required to set theapparatus. However, in Embodiment 6, since double link mechanism isconstituted by using two connecting members, the holder 2 can be swungto be lifted up to about 60°. In addition, since the link mechanism isformed by employing two short connecting members, the space occupied bythe apparatus can be saved.

The link mechanisms shown in Embodiments 5 and 6 may be applied to thesubstrate inspecting apparatuses shown in Embodiments 1 to 4.

FIG. 14 is a perspective view showing the position detector employed inthe substrate inspecting apparatus of Embodiment 7. In FIG. 14, the samereference numerals as used in FIG. 1 denote structural elements similaror corresponding to those of the foregoing embodiments. The positiondetector is applied to the substrate inspecting apparatus described inrelation to Embodiment 1.

Referring to FIG. 14, holding members 7011 and 7012 are attached to theY-axis direction side surfaces of a holder 2. A holding member 702 isattached to an X-axis direction side surface of the holder 2. The uppersurfaces of the holding members 7011, 7012 and 702 are located lowerthan the upper surface of the holder 2, so that there is a step betweenthe holder 2 and the holding members. Guide rails 7031 and 7032 areprovided for the holding members 7011 and 7012 in such a manner thatthey extend along the Y-axis direction sides of the holder 2. Guidemovement members 7051 and 7052 are mounted on the guide rails 7031 and7032 so that they are slidable along the guide rails 7031 and 7032.Likewise, guide rail 704 is provided for the holding member 702 in sucha manner that it extends along an X-axis direction side of the holder 2.A guide movement member 706 is mounted on the guide rail 704 so that itis slidable along the guide rail 704.

Pulleys 709 and 710 are rotatably supported at the respective ends ofthe holding member 702. A belt 712 is wound around the pulleys 709 and710 to form a loop. The guide movement member 706 is in engagement withpart of the belt 712. The pulley 710 is coupled to the rotating shaft716 of a motor 714. On one of the X-axis direction side surfaces of theholder 2, optical sensors 719 and 720 are provided. The sensors 719 and720 detect the guide movement member 706 when this member come intotheir detection regions.

A Y-axis direction reflecting member (e.g., a mirror) 707 is provided onthe guide movement member 706. The reflecting member 707 stands uprighton the member 706 or at an acute angle with reference thereto. A holdingmember 721 having substantially the same height as the holder 2 isprovided at the position where holding members 7011 and 702 intersectwith each other. A laser light source 21 is arranged on the holdingmember 721 in such a manner that it is located on an extension of theguide rail 704. The laser light source 21 is made up of a laser lightsource section 211 and cylindrical lenses 212 and 213, which are shownin FIG. 5.

Pulleys 7071 and 7081 are rotatably supported at the respective ends ofthe perpendicular surface 7013 of holding member 7011, and pulleys 7072and 7082 are rotatably supported at the respective ends of theperpendicular surface 7014 of holding member 7012. A belt 7111 is woundaround pulleys 7071 and 7081 to form a loop, and a belt 7112 is woundaround pulleys 7072 and 7082 to form a loop. Guide movement member 7051is in engagement with part of belt 7111; likewise, guide movement member7052 is in engagement with part of belt 7112. The pulley 7071 is coupledto the rotating shaft 7131 of a motor 713. On one of the Y-axisdirection side surfaces of the holder 2, optical sensors 717 and 718 areprovided. The sensors 717 and 718 detect the guide movement member 7051when this member come into their detection regions. A coupling shaft 730is arranged under the holder 2, and the ends of this coupling shaft 730are rotatably inserted into the hollow sections of the pulleys 7081 and7082, respectively.

Support columns 741 and 742 are rotatably coupled to those side walls ofthe guide movement members 7051 and 7052 which are closer to the holder2. The ends of an elongated projection plate 743 are attached to thetops of the respective support columns 741 and 742. The projection plate743 has a black surface, for example, and is slanted at an angle ofabout 45° with reference to the surface of the substrate 3 underinspection. The side edge of the projection plate 743 is directed towardthe reflector 707. In this state, the support columns 741 and 742 standupright with reference to the surface of the substrate 3.

The projection plate 743 moves in accordance with the synchronousmovement between the guide movement members 7051 and 7052. That is, theplate 743 moves in the Y-axis direction in parallel to the surface ofthe substrate 3, i.e., with a certain distance maintained. As will bedescribed later, a guide member 744 for rotating the support column 741is fixed to the guide rail 7031 at a position that is in theneighborhood of the holding member 721 and close to the holder 2.

A laser beam emitted from the laser light source section 211 of thelight source 21 and transmitted through the cylindrical lenses 212 and213 is in the form of a plane that is substantially orthogonal to thesurface of the substrate 3. The laser beam in this form first travels inthe X-axis direction, and is then reflected 90° by the reflector 707 sothat the reflected laser beam travels in the Y-axis direction. Thereflected laser beam 750 is in the form of a plane substantiallyorthogonal to the surface of the substrate 3, and in this state falls onthe inclined surface of the projection plate 743.

As shown in FIG. 2, the holding member 702 attached to the proximal endof the holder 2 is supported by the supporting shaft 15 in such a manneras to be rotatable with reference to the main apparatus 1. Owing to thisstructure, the holder 2 can be raised at a predetermined angle, orswung, as indicated by the two-dot-dash line in FIG. 2.

With the holder 2 raised at the predetermined angle, the inspectorilluminates the surface of the substrate 3 by macro illumination, asshown in FIG. 6. If a defect a is found on the substrate 3 during thismacro observation, the inspector operates the operation section (e.g., ajoy stick) to drive the motor 714. With the rotating shaft 716 moved inone direction or another, the belt 712 is moved in one direction oranother along the X axis through the pulleys 710 and 709. The reflector707 on the guide movement member 706 is moved along the guide rail 704with reference to the defect a on the substrate 3, until the laser beam750 falls on the defect a.

Further, the inspector operates the operation section to drive the motor713. With the rotating shaft 7131 moved in one direction or another, thebelt 7111 is moved in one direction or another along the Y axis throughthe pulleys 7071 and 7081. In accordance with this movement, the supportcolumn 741 and the projection plate 743 are moved as well as the guidemovement member 7051, such that they move along the guide rail 7031 withreference to the defect a on the substrate 3. The support column 741 andthe projection plate 743 are moved until the lower side 7431 of theprojection plate 743 comes to the position above the defect a. Inaccordance with the rotation of pulley 7081, pulley 7082 is rotated inthe same direction as pulley 7081 by the coupling shaft 730. Belt 7112is driven by the pulleys 7072 and 7082 in the same direction as belt7111. Since, therefore, the guide movement members 7051 and 7052synchronously move in the same direction along the Y axis, theprojection plate 743 moves in the Y-axis direction in parallel to the Xaxis at all times.

Subsequently, the inspector turns on a foot switch. The values of guidescales (not shown) extending along the guide rails 7031 and 704 aredetected as position coordinates (X, Y) of the defect a by detectors(not shown) of the guide scales. That is, the Y-axis direction movingamount of the projection plate 743, as measured from a predeterminedorigin, and the X-axis direction moving amount of the reflector 707, asmeasured from a predetermined origin, are detected. Results of thisdetection are output from the detectors to the controller 11.

If the guide movement member 7051 is sensed by sensor 717 or 718, thecontroller 11 automatically stops the driving of the motor 713. Thismeans that the guide movement member 7051 is allowed to reciprocatealong the guide rail 7031 between the two positions corresponding to thesensors 717 and 718. Similarly, if the guide movement member 706 issensed by sensor 719 or 720, the controller 11 automatically stops thedriving of the motor 714. This means that the guide movement member 706is allowed to reciprocate along the guide rail 704 between the twopositions corresponding to the sensors 719 and 720.

FIGS. 15A to 15D show a mechanism for retracting the projection plate743. FIG. 15A is a plan view showing the guide movement member 7051along with its neighboring portions. FIG. 15B is a side view of theguide movement member 7051. FIG. 15C is a plan view showing the guidemovement member 744 along with its neighboring portions. FIG. 15D is aside view of the guide movement member 744. When the projection plate743 is being moved to the position above the defect a, the supportcolumns 741 and 742 are upright, and the projection plate 743 is locatedabove the substrate 3 such that it is inclined at an angle of 45°, asshown in FIGS. 15A and 15B. The support columns 741 and 742 arerotatably supported by the guide movement members 7051 and 7052 by meansof rotating shafts 7411 and 7421 (not shown).

As indicated by the solid line in FIG. 1, when micro observation isperformed by the micro observation unit 9, with the holder 2 kept in thehorizontal state, the projection plate 743 must be retracted from abovethe substrate 3 so as to avoid collision between the projection plate743 and the objective lens 91. To retract the projection plate 743, theoperator operates the operation section to drive the motor 713. As aresult, the guide movement members 7051 and 7052 are moved toward theholding member 702. When the support column 741 comes into contact withthe guide member 744 shown in FIG. 15C, the projection at the lower endof the support column 741 is gradually moved up along the inclinedsurface 7441 of the guide member 744. In accordance with this movement,the support columns 741 and 742 rotate on the rotating shafts 7411 and7421, respectively, until they become parallel to the substrate 3. Atthe time, the support columns 741 and 742 are fitted in a space extendedfrom the space defined between the holder 2 and the guide rail 704. Inthis retracted state, the support columns 741 and 742 are lower in levelthan the holder 2. Owing to this structure, the collision between theobjective lens 91 and the projection plate 743 can be avoided duringmicro observation.

According to the substrate inspecting apparatus of the seventhembodiment, the position coordinate detecting section can be raisedtogether with the holder 2 even if this holder 2 is raised at any angle.Owing to this structure, a defect position can be reliably detected atall times even if the substrate 3 under inspection is tilted at anyangle. Moreover, since the guide movement members 7051 and 706, whichconstitute the position coordinate detecting section, are electricallydriven, the reflector 707 and projection plate 743 can be easilycontrolled by the operator who operates the operation section. Inparticular, where a large-sized substrate is inspected, a laser beam andthe projection plate 743 are controlled to correspond in position to adefect. The position information on this defect can be easily obtainedeven if the defect is far away from the inspector.

The guide movement members 7051 and 7052 and the projection plate 743can be driven by use of a guide-provided ball screw and a linear motor.In addition, the light source may be a type which, like an LED, flashesand emits a collimated beam. Such a light source may be provided for theguide movement member 706, replacing the reflector 707. Moreover, theprojection plate 743 need not be limited to an elongated plate; it maybe a linear member or a triangle pole as long as a slit beam or a spotbeam, such as that of a laser beam, can be projected thereon.

According to the present invention, the following functions areobtained.

According to the substrate inspecting apparatus of the presentinvention, the substrate holding member can be raised at a predeterminedangle while holding the substrate. It is therefore possible to performthe macro observation of the surface of the substrate from a positionclose to the eye of an inspector. Hence, the defect can be inspectedhighly accurately. In addition, since the position coordinates of thedefect present in the substrate are determined by the position detector,the micro observation system is controlled on the basis of thecoordinates so as to correspond to the defect present in the substrate.As a result, the micro observation can be made smoothly and continuouslyfollowing the macro observation, increasing the efficiency of the defectinspection by the macro observation and the micro observation.

According to the substrate inspecting apparatus of the presentinvention, it is possible to determine the position coordinates of thedefect easily only by detecting the position of the position detectorcorresponding to the defect while moving the position detector along theguide scale provided along the side edge of the substrate.

According to the substrate inspecting apparatus of the presentinvention, the observation unit can be moved in any position on thesubstrate only by moving the observation unit supporting section on thesubstrate in one direction and moving the observation unit in thedirection perpendicular to the moving direction of the observation unitsupporting section. It is therefore possible to form the substrateholding member in virtually the same size as the substrate. Hence,miniaturization of the apparatus is attained and the setting area of theapparatus can be drastically reduced.

Furthermore, in the present substrate inspecting apparatus, theelectrical wiring for providing the light source section on the guidescale can be made simply by moving the reflector. In addition, the spacerequired for the wiring can be reduced. Hence the miniaturization of theapparatus is attained. Since the apparatus can be constituted by usingonly one light source, the apparatus can be formed inexpensively.

According to the substrate inspecting apparatus of the presentinvention, the movement of the reflector can be controlled by apredetermined manual operation the inspector performed at a proximalside of the apparatus. Therefore, in a specific case where a largesubstrate is inspected, the positional data of the defect can be easilyobtained even if the defect is present far away from the inspector.

According to the substrate inspecting apparatus of the presentinvention, a connecting function is used to swing the substrate holdingmember. It is therefore possible to lift up the substrate holding memberup to an angle of about 30°. Since the substrate holding member issupported by the connecting function when lifted up, the macroobservation is performed while the substrate holding member is placed ina stable state.

According to the substrate inspecting apparatus of the presentinvention, the connecting function is constituted of a plurality ofconnecting members. It is therefore possible to lift up the substrateholding member in a swinging manner to an angle of about 60°.Furthermore, the link mechanism is constituted by using a plurality ofshort connecting members. It is therefore possible to save the space forsetting the apparatus.

To be more specifically, the present invention makes it possible notonly to reduce the size of the substrate inspecting apparatus but alsoto increase the accuracy and efficiency in inspection of the substrateinspecting apparatus.

Note that the present invention is not limited to the aforementionedEmbodiments and may be modified within the scope of the presentinvention.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. An apparatus for inspecting a substratecomprising: substrate holding means for holding a substrate to beinspected; driving means for raising the substrate holding means from ahorizontal state to a predetermined angle; position coordinate detectingmeans provided at side edge of the substrate in at least two directions,for detecting position coordinates of a defect present in the substrate;observation system supporting means provided for supporting a microobservation system and moving on a surface of the substrate; andcontrolling means for controlling movement of the micro observationsystem supported by the observation system supporting means tocorrespond to the defect present in the substrate, based on the positioncoordinates of the defect determined by the position coordinatedetecting means.
 2. The apparatus for inspecting a substrate accordingto claim 1, wherein said position coordinate detecting means comprises:a guide scale provided along the side edge of the substrate; and aposition coordinate detecting section movably provided along the guidescale, for detecting a position of the defect present in the substrate.3. The apparatus for inspecting a substrate according to claim 1,wherein the observation system supporting means comprises observationunit supporting means arranged movably in one direction of the surfaceof the substrate so as to cross over the substrate holding means, forsupporting the observation unit including the micro observation system;said observation unit being provided movably on the surface of thesubstrate in the direction perpendicular to the moving direction of theobservation unit supporting means.
 4. The apparatus for inspecting asubstrate according to claim 1, wherein the position coordinatedetecting means comprises a guide scale provided along a side edge ofthe substrate; a light source section for emitting light; reflectingmeans movably provided along the guide scale, for reflecting lightemitted from the light source section toward the substrate side; and adetecting section for detecting the position coordinates of the defecton the basis of a position of the reflecting means on the guide scalewhen the defect is irradiated with light reflected by the reflectingmeans.
 5. The apparatus for inspecting a substrate according to claim 4,wherein the light emitted from the light source section and reflected bythe reflecting means is virtually perpendicular to the surface of thesubstrate.
 6. The apparatus for inspecting a substrate according toclaim 1, wherein the position coordinate detecting means comprises: twoguide scales provided respectively along side edges of the substrate intwo directions; a light source section for emitting light; splittingmeans for splitting the light emitted from the light source section intolight beams in two directions; two reflecting means movably providedalong the two guide scales respectively, each reflecting the light beamsplit by the splitting means toward the substrate side; a detectingsection for detecting the position coordinates of the defect on thebasis of the positions of the reflecting means on the two guide scaleswhen the defect is irradiated with two light beams reflected by the tworeflecting means.
 7. The apparatus for inspecting a substrate accordingto claim 6, wherein the light emitted from the light source section andreflected by the two reflecting means respectively, is virtuallyperpendicular to the surface of the substrate.
 8. The apparatus forinspecting a substrate according to claim 1, wherein the positioncoordinate detecting means comprises two guide scales provided along theside edges of the substrate in two directions; two light source sectionsfor emitting light; two reflecting means movably provided respectivelyalong the two guide scales, for reflecting light emitted from either oneof the two light source sections toward the substrate side; anddetecting means for detecting the position coordinates of the defect onthe basis of positions of the two reflecting means on the correspondingguide scales when the defect is irradiated with two light beamsreflected respectively by the two reflecting means.
 9. The apparatus forinspecting a substrate according to claim 8, wherein the light beamsemitted from the light source sections and reflected by the tworeflecting means are virtually perpendicular to the surface of thesubstrate.
 10. The apparatus for inspecting a substrate according toclaim 1, wherein the position coordinate detecting means comprises twoguide scales respectively provided along the side edges of the substratein two directions; two light source sections movably provided along thetwo guide scales respectively, for emitting light toward the substrateside; and detecting means for detecting the position coordinates of thedefect on the basis of positions of the two light source sections on thecorresponding guide scales when the defect is irradiated with two lightbeams respectively emitted from the two light source sections.
 11. Theapparatus for inspecting a substrate according to claim 10, wherein thelight emitted from each of the light source section is virtuallyperpendicular to the surface of the substrate.
 12. The apparatus forinspecting a substrate according to claim 1, wherein the positioncoordinate detecting means comprises a guide scale provided along theside edge of the substrate; and a position detector provided movablyalong the guide scale by electrical driving force, for detecting aposition of the defect present in the substrate.
 13. The apparatus forinspecting a substrate according to claim 1, wherein the positioncoordinate detecting means comprises two guide scales respectivelyprovided along the side edges of the substrate in two directions; alight source section for emitting light; split means for splitting lightemitted from the light source section into light beams in the twodirections; two reflecting means movably provided respectively along theguide scales, for reflecting the light beams split by the splittingmeans toward a substrate side; two moving means for respectively movingthe two reflecting means along the corresponding guide scales byelectrical driving force; a detector for detecting position coordinatesof the defect on the basis of the positions of the reflecting means onthe two guide scales when the defect is irradiated with two light beamsrespectively reflected by the two reflecting means.
 14. The apparatusfor inspecting a substrate according to claim 13, wherein each of thetwo moving means comprises a motor, two pulleys and a belt driven by themotor.
 15. The apparatus for inspecting a substrate according to claim13, wherein the light emitted from the light source section andreflected by the two reflecting means is virtually perpendicular to thesurface of the substrate.
 16. The apparatus for inspecting a substrateaccording to claim 1, wherein the positions coordinate detecting meanscomprises two guide scales provided respectively along the side edges ofthe substrate in two directions; two light source sections for emittinglight; two reflecting means movably provided respectively along theguide scales, for reflecting light emitted from either one of the twolight source sections toward a substrate side; two moving means formoving the two reflecting means along the corresponding guide scales byelectrical driving force; and a detector for detecting the positioncoordinates of the defect on the basis of the positions of thereflecting means on the two guide scales when the defect is irradiatedwith two light beams reflected respectively by the two reflecting means.17. The apparatus for inspecting a substrate according to claim 16,wherein each of the two moving means comprises a motor, two pulley and abelt driven by the motor.
 18. The apparatus for inspecting a substrateaccording to claim 16, wherein the light beams emitted from the lightsource sections and respectively reflected by the two reflecting meansare virtually perpendicular to the surface of the substrate.
 19. Theapparatus for inspecting a substrate according to claim 1, wherein saiddriving means comprising: moving means for moving back and forth withrespect to the substrate holding means; connecting means connected tothe substrate holding means and the moving means, for swinging thesubstrate holding means with movement of the moving means.
 20. Theapparatus for inspecting a substrate according to claim 19, wherein saidconnecting means is formed by connecting a plurality of connectingmembers, said connecting member being rotatable to a connectionreceptor.
 21. The apparatus for inspecting a substrate according toclaim 1, wherein said position coordinate detecting means includes: afirst guide rail extending in one direction along a side edge of thesubstrate to be inspected; a pair of second guide rails extending inanother direction along side edges of the substrate to be inspected; alight source being movable along the first guide rail, said light sourceemitting light in a direction orthogonal to said one direction; aprojection member bridging the substrate and being movable along thesecond guide rails, the light emitted from the light source beingprojected on the projection member; and a detection section fordetecting position coordinates of the defect based on where on the firstguide rail the reflecting means is located and where on the second guiderails the projection member is located, said detection section detectingthe position coordinates when the light emitted from the light sourcefalls on the defect and the projection member is located above thedefect.
 22. The apparatus for inspecting a substrate according to claim21, further comprising: two driving means for electrically moving theprojection member along the second guide rails, one of said two drivingmeans including a motor, and each of said two driving means includingtwo pulleys and a belt which are driven by the motor; and a couplingshaft coupling one of the two pulleys of one of said two driving meansto one of the two pulleys of another one of said two driving means. 23.The apparatus for inspecting a substrate according to claim 21, furthercomprising: a retracting mechanism for retracting the projection memberfrom above the substrate.